tTARGIT AAVs mediate the sensitive and flexible manipulation of intersectional neuronal populations in mice
Paul V. Sabatini, Jine Wang, Alan C. Rupp, Alison H. Affinati, Jonathan N. Flak, Chien Li, David P. Olson, Martin G. Myers
Abstract
While Cre-dependent viral systems permit the manipulation of many neuron types, some cell populations cannot be targeted by a single DNA recombinase. Although the combined use of Flp and Cre recombinases can overcome this limitation, insufficient recombinase activity can reduce the efficacy of existing Cre+Flp-dependent viral systems. We developed a sensitive dual recombinase-activated viral approach: tTA-driven Recombinase-Guided Intersectional Targeting (tTARGIT) adeno-associated viruses (AAVs). tTARGIT AAVs utilize a Flp-dependent tetracycline transactivator (tTA) ‘Driver’ AAV and a tetracycline response element-driven, Cre-dependent ‘Payload’ AAV to express the transgene of interest. We employed this system in Slc17a6 FlpO ;Lepr Cre mice to manipulate LepRb neurons of the ventromedial hypothalamus (VMH; LepRb VMH neurons) while omitting neighboring LepRb populations. We defined the circuitry of LepRb VMH neurons and roles for these cells in the control of food intake and energy expenditure. Thus, the tTARGIT system mediates robust recombinase-sensitive transgene expression, permitting the precise manipulation of previously intractable neural populations.